Uniforms and protective clothing, often referred to as PPE (Personal Protective Equipment), worn by military, rescue and maintenance personnel sometimes incorporate liquid cooling features to minimize the risk of overheating under extreme environmental conditions, for example, desert climates, fire, or high temperature industrial operations, or due to weight, density or lack of breathability, such as explosion, hazardous material or radiation shielding. There are two basic cooling approaches, active and static, each having advantages and disadvantages. Static devices, such as ice vests, do not circulate any coolant, but work on convective heat transfer. They must be worn by the user to be effective. Active cooling systems have the advantage of controlled cooling rate with the cooling liquid supplied by almost any heat sink source. The circulation function in active devices is typically provided by a pump and reservoir in a vehicle or structure that the wearer plugs into by means of a connector that seals the liquid conduit to prevent loss of coolant or introduction of air or other contaminants into the conduit during connection and release. In situations where it becomes necessary to abruptly uncouple the fluid conduits, it is desirable to provide a means for rapidly automatically disconnecting the coupling without damaging the conduits or the coupling such that rapid re-coupling cannot occur without requiring repair. Further, the act of uncoupling, even when done suddenly, should occur without fluid leakage.
In general, all liquid connectors have seals to control liquid loss. Simple designs have outer seals that seal while the connectors are coupled but do not prevent flow when disconnected. More complex connectors used valves to reduce or eliminate flow when the connector components are separated. A number of detachable fluid conduit coupling systems are known in the prior art. Many such devices employ spring-loaded ball-type valves that may reduce the loss of process fluid upon uncoupling. Examples of such systems are described in U.S. Pat. No. 4,105,046 of Sturgis, and U.S. Pat. No. 5,092,364 of Mullins. Systems of this type fail to provide means for preventing the introduction of contaminants such as air and ambient fluids into the process fluid upon coupling.
All connectors require some form of releasable locking mechanism, usually a push button or other trigger to separate the connector halves. One of the more important components of fluid conduit couplings that are used for personnel cooling is an auto release that allows the connector to be separated without the user initiating any action. Such couplings typically have a break force designed to match specifications for the particular application.
Most fluid coupling systems of the prior art are not adapted to allow damage-free separation of the connector ends upon the application of tensile force when a manual release mechanism has not been actuated. This can result in the loss of significant quantities of process fluid due to conduit rupturing when emergency separation becomes necessary. In situations where the process fluid is potentially dangerous, release of the fluid can pose a substantial hazard.
U.S. Pat. No. 6,547,284, which is incorporated herein by reference, describes a fluid conduit coupling that allows quick connection and disconnection with substantially no introduction of ambient fluids or air into the process fluid. The latch can be disconnected by activation of a manual release or by the application of a predetermined tensile force, which is determined by spring specification. One disadvantage of this device is that the spring must exert exactly the same force for each connector set in order to provide repeatable performance. Due to inherent manufacturing variations, the springs used in this connector tend to vary in force from one to another. Further, for the required disconnect force to be uniform, the spring must exert the same amount of break force at each point in the circumferential axis. However, by their very design, single helix springs are incapable of exerting the same force around the entire circumferential axis, and mere rotation of the spring, which occurs normally in this design, will produce a difference in force. In addition, the latching surfaces, with a single contact point, are located a distance from the fulcrum for latching such that the surface finish of the parts becomes critical to the amount of force required for delatching. Any change in the surface finish amplifies a change in the break force. Further, due to the use of a single contact point, an abrupt force applied perpendicular to the connector axis will cause the coupling to delatch. An additional disadvantage is that there is no means provided for adjusting the break force.
Accordingly, the need remains for a quick-disconnect connector for fluid conduits that will automatically and reliably disengage upon application of a predetermined break force that can be adjusted by the user to meet the application The present invention is directed to such a connector.